Make sure float4in/float8in accept all standard spellings of "infinity".

The C99 and POSIX standards require strtod() to accept all these spellings
(case-insensitively): "inf", "+inf", "-inf", "infinity", "+infinity",
"-infinity".  However, pre-C99 systems might accept only some or none of
these, and apparently Windows still doesn't accept "inf".  To avoid
surprising cross-platform behavioral differences, manually check for each
of these spellings if strtod() fails.  We were previously handling just
"infinity" and "-infinity" that way, but since C99 is most of the world
now, it seems likely that applications are expecting all these spellings
to work.

Per bug #8355 from Basil Peace.  It turns out this fix won't actually
resolve his problem, because Python isn't being this careful; but that
doesn't mean we shouldn't be.

diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 91df2179a0c7f2c67c0ccdb7c14fc1cfd6dbac89..b6c31c2fd928936f2bd4b5a842e2d6ea058bd3ba 100644 (file)
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -176,11 +176,7 @@ is_infinite(double val)
 
 
 /*
- *     float4in        - converts "num" to float
- *                       restricted syntax:
- *                       {<sp>} [+|-] {digit} [.{digit}] [<exp>]
- *                       where <sp> is a space, digit is 0-9,
- *                       <exp> is "e" or "E" followed by an integer.
+ *     float4in        - converts "num" to float4
  */
 Datum
 float4in(PG_FUNCTION_ARGS)
@@ -197,6 +193,10 @@ float4in(PG_FUNCTION_ARGS)
     */
    orig_num = num;
 
+   /* skip leading whitespace */
+   while (*num != '\0' && isspace((unsigned char) *num))
+       num++;
+
    /*
     * Check for an empty-string input to begin with, to avoid the vagaries of
     * strtod() on different platforms.
@@ -207,10 +207,6 @@ float4in(PG_FUNCTION_ARGS)
                 errmsg("invalid input syntax for type real: \"%s\"",
                        orig_num)));
 
-   /* skip leading whitespace */
-   while (*num != '\0' && isspace((unsigned char) *num))
-       num++;
-
    errno = 0;
    val = strtod(num, &endptr);
 
@@ -220,9 +216,14 @@ float4in(PG_FUNCTION_ARGS)
        int         save_errno = errno;
 
        /*
-        * C99 requires that strtod() accept NaN and [-]Infinity, but not all
-        * platforms support that yet (and some accept them but set ERANGE
-        * anyway...)  Therefore, we check for these inputs ourselves.
+        * C99 requires that strtod() accept NaN, [+-]Infinity, and [+-]Inf,
+        * but not all platforms support all of these (and some accept them
+        * but set ERANGE anyway...)  Therefore, we check for these inputs
+        * ourselves if strtod() fails.
+        *
+        * Note: C99 also requires hexadecimal input as well as some extended
+        * forms of NaN, but we consider these forms unportable and don't try
+        * to support them.  You can use 'em if your strtod() takes 'em.
         */
        if (pg_strncasecmp(num, "NaN", 3) == 0)
        {
@@ -234,11 +235,31 @@ float4in(PG_FUNCTION_ARGS)
            val = get_float4_infinity();
            endptr = num + 8;
        }
+       else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+       {
+           val = get_float4_infinity();
+           endptr = num + 9;
+       }
        else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
        {
            val = -get_float4_infinity();
            endptr = num + 9;
        }
+       else if (pg_strncasecmp(num, "inf", 3) == 0)
+       {
+           val = get_float4_infinity();
+           endptr = num + 3;
+       }
+       else if (pg_strncasecmp(num, "+inf", 4) == 0)
+       {
+           val = get_float4_infinity();
+           endptr = num + 4;
+       }
+       else if (pg_strncasecmp(num, "-inf", 4) == 0)
+       {
+           val = -get_float4_infinity();
+           endptr = num + 4;
+       }
        else if (save_errno == ERANGE)
        {
            /*
@@ -287,6 +308,11 @@ float4in(PG_FUNCTION_ARGS)
            val = get_float4_infinity();
            endptr = num + 8;
        }
+       else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+       {
+           val = get_float4_infinity();
+           endptr = num + 9;
+       }
        else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
        {
            val = -get_float4_infinity();
@@ -382,10 +408,6 @@ float4send(PG_FUNCTION_ARGS)
 
 /*
  *     float8in        - converts "num" to float8
- *                       restricted syntax:
- *                       {<sp>} [+|-] {digit} [.{digit}] [<exp>]
- *                       where <sp> is a space, digit is 0-9,
- *                       <exp> is "e" or "E" followed by an integer.
  */
 Datum
 float8in(PG_FUNCTION_ARGS)
@@ -402,6 +424,10 @@ float8in(PG_FUNCTION_ARGS)
     */
    orig_num = num;
 
+   /* skip leading whitespace */
+   while (*num != '\0' && isspace((unsigned char) *num))
+       num++;
+
    /*
     * Check for an empty-string input to begin with, to avoid the vagaries of
     * strtod() on different platforms.
@@ -412,10 +438,6 @@ float8in(PG_FUNCTION_ARGS)
             errmsg("invalid input syntax for type double precision: \"%s\"",
                    orig_num)));
 
-   /* skip leading whitespace */
-   while (*num != '\0' && isspace((unsigned char) *num))
-       num++;
-
    errno = 0;
    val = strtod(num, &endptr);
 
@@ -425,9 +447,14 @@ float8in(PG_FUNCTION_ARGS)
        int         save_errno = errno;
 
        /*
-        * C99 requires that strtod() accept NaN and [-]Infinity, but not all
-        * platforms support that yet (and some accept them but set ERANGE
-        * anyway...)  Therefore, we check for these inputs ourselves.
+        * C99 requires that strtod() accept NaN, [+-]Infinity, and [+-]Inf,
+        * but not all platforms support all of these (and some accept them
+        * but set ERANGE anyway...)  Therefore, we check for these inputs
+        * ourselves if strtod() fails.
+        *
+        * Note: C99 also requires hexadecimal input as well as some extended
+        * forms of NaN, but we consider these forms unportable and don't try
+        * to support them.  You can use 'em if your strtod() takes 'em.
         */
        if (pg_strncasecmp(num, "NaN", 3) == 0)
        {
@@ -439,11 +466,31 @@ float8in(PG_FUNCTION_ARGS)
            val = get_float8_infinity();
            endptr = num + 8;
        }
+       else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+       {
+           val = get_float8_infinity();
+           endptr = num + 9;
+       }
        else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
        {
            val = -get_float8_infinity();
            endptr = num + 9;
        }
+       else if (pg_strncasecmp(num, "inf", 3) == 0)
+       {
+           val = get_float8_infinity();
+           endptr = num + 3;
+       }
+       else if (pg_strncasecmp(num, "+inf", 4) == 0)
+       {
+           val = get_float8_infinity();
+           endptr = num + 4;
+       }
+       else if (pg_strncasecmp(num, "-inf", 4) == 0)
+       {
+           val = -get_float8_infinity();
+           endptr = num + 4;
+       }
        else if (save_errno == ERANGE)
        {
            /*
@@ -492,6 +539,11 @@ float8in(PG_FUNCTION_ARGS)
            val = get_float8_infinity();
            endptr = num + 8;
        }
+       else if (pg_strncasecmp(num, "+Infinity", 9) == 0)
+       {
+           val = get_float8_infinity();
+           endptr = num + 9;
+       }
        else if (pg_strncasecmp(num, "-Infinity", 9) == 0)
        {
            val = -get_float8_infinity();